Establishment of a visual gene knockout system based on CRISPR/Cas9 for the rare actinomycete Nonomuraea gerenzanensis.

OBJECTIVES: To develop a modified CRISPR/Cas9 system with the ß-glucuronidase (GusA) reporter and a dual sgRNA cassette for Nonomuraea gerenzanensis (N. gerenzanensis). RESULTS: With the aid of a visual GusA reporter, the complicated and tedious process of cloning and gene identification could be abandoned entirely in the genetic editing of N. gerenzanensis. Moreover, introducing a dual sgRNA cassette into the CRISPR/Cas9 system significantly improved gene deletion efficiency compared to the single sgRNA element. Furthermore, the length of the homologous flanking sequences set to the lowest value of 500 bp in this system could still reach the relatively higher conjugation transfer frequency. CONCLUSIONS: The enhanced CRISPR/Cas9 system could efficiently perform genetic manipulation on the rare actinomycete N. gerenzanensis.

miR-96 promotes cell proliferation, migration and invasion by targeting PTPN9 in breast cancer.

microRNAs (miRNAs) have emerged as major regulators of the initiation and progression of human cancers, including breast cancer. The aim of this study is to determine the expression pattern of miR-96 in breast cancer and to investigate its biological role during tumorigenesis. We showed that miR-96 was significantly upregulated in breast cancer. We then investigated its function and found that miR-96 significantly promoted cell proliferation, migration and invasion in vitro and enhanced tumor growth in vivo. Furthermore, we explored the molecular mechanisms by which miR-96 contributes to breast cancer progression and identified PTPN9 (protein tyrosine phosphatase, non-receptor type 9) as a direct target gene of miR-96. Finally, we showed that PTPN9 had opposite effects to those of miR-96 on breast cancer cells, suggesting that miR-96 may promote breast tumorigenesis by silencing PTPN9. Taken together, this study highlights an important role for miR-96 in the regulation of PTPN9 in breast cancer cells and may provide insight into the molecular mechanisms of breast carcinogenesis.